Athletics Kenya’s chief executive has asked to step aside for 21 days pending an investigation into allegations that he sought bribes to reduce the doping bans of two Kenyan athletes who failed drugs tests, the federation said on Tuesday.

Isaac Mwangi last week dismissed as “fabrication” accusations by Joy Sakari and Francisca Koki Manunga that he had asked each athlete for US$24,000 to reduce their four-year bans. The two runners were caught doping in August at the world championships in Beijing, where Kenya topped the medals table.

“I am anxious to have my name cleared,” he added, according to the letter dated February 15.

Kenya is a global leader in endurance running, both on the track and in big-city marathons, but more than 40 of its athletes have been banned for doping in the past three years.

The allegations have caused me a lot of mental anguish. I am anxious to have my name cleared

Kenyan athletics chief Isaac Mwangi

The spike in doping, coupled with corruption allegations against top AK officials over the past year, has stoked fears in Kenya that the East African nation could follow Russia and be suspended from global athletics.

The doping crisis in Russia and Kenya, as well as allegations of corruption within the world governing body, the IAAF, have cast a shadow over the sport ahead of the Rio Olympics in August.

Jack Tuwei, the AK president, said the newly formed Anti-Doping Agency of Kenya (Adak) would conduct the investigation into allegations against Mwangi and report findings in two weeks.

“If cleared, [Mwangi] will come back,” said Tuwei.

He added that the World Anti-Doping Agency (Wada) and the IAAF Ethics Commission had been in touch about the allegations.

Wada last week said it was “extremely troubled” by reports against Mwangi, adding that they were “eerily similar sounding” to what had been learned through an independent commission investigation into widespread doping in international athletics.

Tuwei’s predecessor, Isaiah Kiplagat, and two other senior AK officials, are being investigated by the IAAF over corruption allegations during their tenures at the federation. All three deny any wrongdoing.

Kenya last week missed a deadline to prove to Wada that it was doing enough to combat doping and faces being declared a non-compliant nation, which could lead to a global ban. But AK officials, including Mwangi, say Kenya has increased efforts to root out doping ahead of the Rio Olympics.